Device for separating two superimposed moving sheets



Nov. 14, 1967 u. MENZI ETAL DEVICE FOR SEPARATING TWO 'SUPERIMPOSEDMOVING SHEETS Filed July 5, 1966 2 Sheets-Sheet l Ulric/'1 MenzL HeLrhut G'rr ger-e'ds Nov. 14, 1957 'u. MENZI ETAL 3,352,554

DEVICE FOR SEPARATING TWO SUPERIMPOSED MOVING SHEETS Filed July 5, 19662 Sheets-Sheet 2 a Q amaaamwgwqguymwaragm 5 5 5 5 *xmwxmmwmwmmm ULrfcJwMenzi. HeLmu'lz Grl'yere'rl:

1M, JW 2, Wm My United States Patent 9 Claims. (Cl. 271-64) Theinvention relates to a device for separating two superimposed movingsheets.

A separating device has been proposed for use in a blueprint copyingapparatus, for example, and comprises a separating element spaced from afeed cylinder the separating element being a second cylinder whichoperates as a feed cylinder for the conveying of the superimposed sheetsuntil operation of a switch reverses the direction of rotation thereofthe switch being operated by the sheets which are to be separated. Oneof the first disadvantages of this device can be seen in the fact thatas soon as the sheet opposite the separating cylinder (copy) has beenlifted up the second cylinder then rubs against the back of theoriginal, which remains between the two cylinders, and thereby tends topush this back also. As a result of the difiercnt directions of rotationof the cylinders, great stress is imposed on the original and this canlead to serious damage of the original, particularly in the case of thinand/or especially delicate originals. Moreover, to secure a satisfactorycontinuance of the feed of the original, which is now heavily braked, anadditional feed device has to be disposed after the separating device.The adjustment of the distance between the two cylinders presentsdifiiculties and makes great demands on the mounting and truth ofrotation of the two cylinders. Finally, the separation of the sheetsdoes not always function perfectly and so the sheet which has beenpushed back is very likely to become tangled in the copying apparatus.This applies especially when the flank of the developing look in thecopy sheet nearest the second cylinder comes into a position tangentialto the second cylinder, so that in fact there is no actual lifting ofthe copy sheet Off the second cylinder.

In order to remedy this last point in particularly, an arrangement wasproposed which made the second cylindere rotate in the backwardtransporting direction all the time and in which the distance betweenthe two cylinders can be so adjusted that at any given time just onesheet only is able to pass therebctween. The difiiculty in thisarrangement lies in the correct adjustment of the distance between thetwo cylinders which must be of such dimensions that one sheet isreliably conveyed through but a second sheet lying thereon is just asreliably held back. For reasons of safety (failure of the separatingdevice) moreover, the original has then to be conveyed through thecylinders; in the case of oflice copying machines however, this maycover the range from very thin (air mail) up to very thick,cardboard-like papers so that the distance has to be set individuallyfor every thickness of the original, which is disadvantageous withregard to the operating of the apparatus.

A further proposed sheet separating device likewise provides, as asolution of this adjusting problem a separating element in the form of acylinder rotating in the backward feed direction which has to be swungin manually into position and then swung out again after the sheets havebeen separated. Of course in a manually operated construction thisarrangement is relatively simple, but with a corresponding automaticform it entails an expenditure which is excessive for the simplerapplications (e.g. the simpler ofiice copying machines).

In conclusion, another proposed separating device subdivides the feedcylinder and also a counter-cylinder rotating in the backward directioninto single, mutually olfset roller and disc segments, thecounter-elements of which are formed of flat belts which are stretchedthrough between the single roller and disc segments. This arrangementreduces the opposed frictional forces acting on the individual sheets tobe separated and yet this solution is also extremely troublesome, makesconsiderable demands on the correct adjustment of rollers and belts andits reliability of functioning is limited.

The object of the invention, therefore, is to create a separating deviceespecially for ofiice copying apparatuses which, at low cost and withthe maximum protection of the sheet material, ensures the perfect andfunctionally dependable separation of two moving sheets, one lying uponthe other.

The invention provides a device for separating two superimposed sheetscomprising (a) a rotatable feed cylinder over which the sheet to beseparated are intended to be passed,

(b) a rotatable shaft spaced from and axially parallel to the feedcylinder,

(c) an outwardly projecting elastic flap mounted on the shaft,

(d) a switch actuatablc by the sheets when at least a part of the sheetshas passed over the feed cylinder,

(c) drive means for rotating the shaft one revolution, when the switchis actuated, in a direction counter to the direction of rotation of thefeed cylinder whereby the flap presses the sheets against the feedcylinder and is deformed such that the sheet adjacent the feed cylinderwill continue in its original direction of travel and the sheet remotefrom the feed cylinder will be deflected into a different direction oftravel.

The advantages of the separating device according to the invention canbe seen from the following points:

(1) The free entry of the sheets which are to be separated into theseparating device preserves the sheet material and simplifiers the entrymechanism.

(2) Through the use of a rotating elastic flap which, under elasticdeformation, presses the sheets which are to be separated for a shorttime against the feed cylinder, the adjustment of the distances betweenthe two separating elements loses its importance.

(3) In consequence of the single rotation of the separating element thesheets to be separated are pressed to gether for a minimum period andany contact between the counter-element and the remaining sheet isprecluded.

(4) As a result of the recoil of the elastically deformed flap into itsposition of rest after the actual separating process, the lifted sheetis flung into its new path and so any entanglement of this sheet in theseparating mechanism is precluded.

The separating device according to the invention and also the couplingelements required for the execution of one single rotation of theseparating element are explained in greater detail in the case of anofiice copying machine below, with reference to the drawings in which:

FIGURE 1 shows in a perspective diagram the essential separatingelements according to the invention;

FIGURES 2-4 are sections through the arrangement in FIGURE 1 showingdifferent stages of the separating process and FIGURE 5 shows theseparating device of FIGURES 1-4 with the associated coupling elements.

As shown in FIGURE 1, rubberized cylinder 1 rotates in the directionmarked by an arrow and acts simultaneously as feed cylinder for sheets 4(copy) and 5 (original) which are to be separated. Disposed above thecylinder 1 and parallel to it is a shaft 2 which is covered with arubber profile 3 which has a flap 3a. In the first phase of theseparating process, shown in FIG- URE 2, the flap is not in contact withthe copy sheet 4 the separating device being in its neutral position.

The sheets are pushed over the cylinder 1 and operate a switch 13 whichinitiates rotation of the shaft 2 in the clockwise direction (FIGURE 2).

FIGURE 3 shows the operational phase of the shaft 2 in which the flap 3apresses the sheets on to the feed cylinder 1. Since the coefficients offriction between the cylinder 1 and the original 5, on the one hand, andbetween the flap 3a and the copy sheet 4, on the other, are greater thanthe coeflicient of friction between the original and the copy sheet 4,the original as moved onwards in the direction of the arrow, while onthe other hand the copy sheet 4 is pushed backwards and therby forms ahump indicated by 4'.

Finally, FIGURE 4 shows a last phase before the shaft 2, or rather theflap 3a, has returned to its neutral position. The flap which has beenbent back considerably in an elastic manner by the counterpressure ofthe cylinder 1 (FIGURE 3) is now released suddenly and jerks back intoits relative neutral position. The sheet 4 thus flung awaysimultaneously by the separating device, so that the risk ofentanglement of the copy in the separating device, cap be eliminated.

The following features are essential to the perfect functioning of thedevice according to the invention:

The shortest distance between the rubber profile 3 on the shaft 2 or thebase of the flap 3a and the surface U of the feed cylinder 1 should beselected to be so small that the flap 3a can just be pulled between theshaft 2 and the feed cylinder 1. This distance depends substantially onthe elasticity of the flap 3a and on the torque which should or can beapplied to the shaft 2. In order to ensure reliable sheet separation,larger flap lengths I must be accepted in the case of greater distances,which however is disadvantageous in its eflect on the separationoperation. It has been found that optimum results are obtained if thedistance between the rubber profile 3 and the periphery U of the feedcylinder is about twice the thickness d of the flap 3a.

The distance s between the point of contact K of the sheet 5 and theperiphery U of the feed cylinder 1 and the feeler of the switch 13triggering the rotation of the shaft 2 is slightly smaller than or equalto the radius r, which is described by the end R of the flap 3a with thelength l on rotation of the shaft 2, the optimum dimensioning dependingon the relative speed between the advance of the sheets 4 or 5 and thespeed of rotation of the shaft 2 or of the flap 3a respectively, takinginto account the retardation time between response of the feeler of theswitch 13 to the beginning of the rotation of the shafts 2. If s issubstantially smaller than r, both sheets 4 and 5 are diverted into thenew path; if on the other hand s is greater than r, the dependablelifting of the sheet 4 off the sheet 5 lying therebeneath is no longerensured.

The mechanical feeler illustrated may also be replaced by a lightbarrier or the like.

Instead of using a profile 3 with a flap 3a extending the whole lengthof the shaft 2 it is possible to use a profile with several individualflaps 3', 3" (FIGURE 5); in this way stiffening, such as occurs aftersome time and with certain materials, especially rubber, in full-lengthflaps can be avoided. Also the fractional pressure on the copy sheet ismore even. It is obvious that other suitable elastic materials apartfrom rubber can be used to form the profile 3.

FIGURE 5 shows a coupling mechanism according to the invention forinitiating a single rotation of the shaft 2. The latter has at its end arigidly mounted driving plate 12 and a sprocket wheel 7 which isstraightened at one place in such a manner that a continuously movingchain 6, which may be the general driving chain for thecopyingapparatus, is prevented from driving the sprocket wheel 7 whenthe separating device is in the neutral position. A magnet 9, thewinding of which is energized by the switch 13 via a lead 14, has anarmature 15 at the free end of which a pawl 11 is articulated. The pawl11, when in the neutral position, engages with a driving pin 10 on V pthe driving plate 12.

When the sheets to be separated enterthe separating device, the switch13 is operated, current flows through the exciting winding of the magnet9 and the armature is drawn up. The pawl 11 turns the driving plate 12through the driving pin 10 in a counterclockwise direction and with itthe shaft 2 and the sprocket wheel 7. The sprocket wheel 7 engages withthe chain 6, whereby a leaf spring 8 ensures correct engagement of theteeth of the sprocket wheel 7 with the links of the chain 6. Thesprocket wheel, driving plate, shaft 2 and rubber profile 3 now executea full revolution. On return to its initial position the sprocket wheel7, owing to pressure from the spring 8 via the chain 6 on the flat chordof the sprocket wheel, remains in the neutral position and hence also dothe shaft 2 and the profile 3.

When the original 5 has finally passed right through the separatingdevice and released the switch 13 again, the armature 15 of the magnet 9drops back into its starting position. The pawl 11 engages with thedriving pin 10 and thus the separating device is now-and not untilnow--ready again for the next separating operation. This precludes falserotations of the shaft 2 and with it the profile 3, which contributessubstantially to the protection of the original 5 and the reliability ofthe separating process.

If, for any reason, there should nevertheless be some failure in theseparating device the original and the copy are passed unseparated tothe delivery point of the copying apparatus. Thus any misdirection ofthe original to some developing and fixing station is renderedimpossible.

Of course the separating device according to the invention can be used,not only in the case of office copying machines, but in all applicationwhere two moving sheets, one on top of the other, have to be separated.

What is claimed is:

p 1. A device for separating two superimposed sheets comprising (a) arotatable feed cylinder over which the sheets to be separated areintended to be passed,

(b) a rotatable shaft spaced from and axially parallel to the feedcylinder,

(c) an outwardly projecting elastic flap mounted on the shaft,

(d) a switch actuatable by the sheets when at least a part of the sheetshas passed over the feed cylinder,

(c) drive means for rotating the shaft one revolution,

when the switch is actuated, in a direction counter to the direction ofrotation of the feed cylinder whereby the flap presses the sheetsagainst the feed cylinder and is deformed such that the sheet adjacentthe feed cylinder will continue in its original direction of travel andthe sheet remote from the feed cylinder will be deflected into adifferent direc tion of travel.

2. The device of claim 1, wherein the elastic flap is a tangentialextension of a sleeve fitted around said shaft, the sleeve being made ofrubber.

3. The device of claim 1, wherein a plurality of elastic flaps ismounted in coplanar relationship on said shaft.

4. The. device of claim 1, wherein the drive means comprises a sprocketwheel mounted at one end of the shaft and rotatable therewith, drivermeans also mounted at said one end and rotatable with said shaft saidsprocket wheel having a flattened portion along one chord thereof, chaindrive means, spring means for urging the chain drive into contact withsaid sprocket wheel, whereby the chain drive will be in drivingengagement with the sprocket wheel except when the chain is in contactwith the flattened portion of said sprocket wheel.

5. The device of claim 4, wherein the driver means consists of a drivingplate, a pin being mounted on said driving plate, the drive meansfurther comprising a magnet energisable on actuation of said switch, anarmature comprised in said magnet, a pawl articulated on said armatureand being normally in engagement with the pin, whereby when the magnetis energised, movement of the armature causes the pawl to urge the pinin a direction such that the driving plate and with it the sprocketWheel rotate whence the sprocket wheel is brought into drivingengagement with the chain drive.

6. The device of claim 1, wherein the distance between base of the flapand the curved surface of the feed cylinder, when the base of the flapis nearest to the feed cylinder, is at least about twice the thicknessof said flap.

7. The device of claim 1, wherein the switch is arranged to actuaterotation of the shaft at an instant such that the outer axially parallelend of the flap Will strike the leading edge of the sheet remote fromthe feed cylinder.

8. The device of claim 7, and comprising a feeler for actuating saidswitch, the feeler being positioned at the intersection of therotational path of the outer axially parallel end of the flap and thepath of the sheets to be separated.

9. The device of claim 8, wherein the distance between the point ofcontact of the sheets to be separated and the feed roller and the feeleris substantially equal to or just less than the radius described by theouter axially parallel end of the flap on rotation of the shaft.

References Cited UNITED STATES PATENTS 3,017,179 12/1962 Stuckens 27118RICHARD E. AEGERTER, Primary Examiner.

1. A DEVICE FOR SEPARATING TWO SUPERIMPOSED SHEETS COMPRISING (A) AROTATABLE FEED CYLINDER OVER WHICH THE SHEETS TO BE SEPARATED AREINTENDED TO BE PASSED, (B) A ROTATABLE SHAFT SPACED FROM AND AXIALLYPARALLEL TO THE FEED CYLINDER, (C) AN OUTWARDLY PROJECTING ELASTIC FLAPMOUNTED ON THE SHAFT, (D) A SWITCH ACTUATABLE BY THE SHEETS WHEN ATLEAST A PART OF THE SHEETS HAS PASSED OVER THE FEED CYLINDER, (E) DRIVEMEANS FOR ROTATING THE SHAFT ONE REVOLUTION WHEN THE SWITCH IS ACTUATED,IN A DIRECTION COUNTER TO THE DIRECTION OF ROTATION OF THE FEED CYLINDERWHEREBY THE FLAP PRESSES THE SHEETS AGAINST THE FEED CYLINDER AND ISDEFORMED SUCH THAT THE SHEET ADJACENT THE FEED CYLINDER WILL CONTINUE INITS ORIGINAL DIRECTION OF TRAVEL AND THE SHEET REMOTE FROM THE FEEDCYLINDER WILL BE DEFLECTED INTO A DIFFERENT DIRECTION OF TRAVEL.